Louvre windows consist of a surround frame formed of upper and lower horizontal frame portions and opposed side frame portions which are fastened together. The frame supports an array of horizontal louvres which pivot about horizontal pivot pins between louvre open and louvre closed positions. It is known to tip the frame on its side such that the louvres extend vertically, however the invention will be described with respect to horizontally extending louvre blades.
For louvre windows, the blades are typically formed of glass (but can be made of other material) and are rectangular when viewed in plan. The blades can have a length of anywhere between 20 to 120 cm, a width of between 10 to 40 cm, and a thickness of between 4 to 20 mm.
As it is not practical to drill holes in glass blades, it is usual for the blades to be supported by end clips. One end clip is pivotally attached to one side frame portion and the other end clip is pivotally attached to the other side frame portion. It is normal for the end clips on one side frame portion to be functionally attached together such that all the end clips can be rotated by a louvre operating mechanism. The end clips on the other side frame portion can usually pivot independently.
In order to reduce water penetration through the louvre window, the blades are in an overlapping configuration when closed, which means that a lower longitudinal edge of an upper blade overlaps the upper longitudinal edge of an adjacent lower blade. It is also known to have end clips configured to seal against each other to minimise water penetration through the end clips. The configuration of the end clip includes a longitudinal rib which seals against the U-shaped aluminium channel as the end clip pivots from the open position to the closed position.
Notwithstanding many attempts to redesign the end clip, water still penetrates through the join between one end clip and a second end clip when the clips are in the closed position. This is exacerbated when there is also a pressure differential between the front of the louvre and the rear of the louvre. A pressure differential often occurs during sudden storms where the pressure inside the room can be appreciably lower than the outside pressure resulting in an air/water mixture being forced between the end clips when the louvres are in the closed position.
Overlapping blades are not very effective in preventing water penetration. Under strong wind and rain conditions, water can be forced uphill between the overlapping closed blades and into the interior of the louvre window. One way to minimise this is to increase the degree of overlap but this increases the size and weight of a louvre window and reduces optical transparency.
One form of the present invention is to provide a redesigned end clip which now has at least one drainage channel to drain water which may pass between one end clip and another end clip. Suitably, a number of drainage channels are provided to greatly reduce the possibility of water penetrating entirely through the end clips.
Conventional louvre operating mechanisms rotate the end clips on one side frame portion by engaging with and rotating the pivot pins. The mechanism is simple as the louvre pivots about a central portion which means that the pivot pin is easily accessible to the mechanism.
A particular disadvantage with conventional louvre mechanisms is the rather large load placed on the operating mechanism when opening or closing a louvre window of the type described above. This requires components to be made of strong material, usually steel which adds to the manufacturing cost. As well, it can be difficult for a person to manipulate a conventional operating mechanism due to the larger loads.
The main reason for the relatively large load being placed on operating mechanism is due to the end clip frictionally engaging with the U-shaped channel as the end clip moves either from the closed position to the open position or from the open position to the closed position. The reason for this is that the end clip is provided with a longitudinal sealing rib or bead which wipes across the U-shaped channel as the clip rotates to the closed position, or away from the closed position. This wiping action places a load on the operating system, and therefore a restriction is placed on the number of louvre blades which can be rotated by a single operating system, typically to about six blades.
It would be an advantage to rotate more blades using a single handle without jeopardising or reducing the sealing action of the end clip. The reason why it would be an advantage is in being able to align the handles horizontally when a number of separate louvre windows are positioned in a single room. That is, if a room contains, say, 3 banks of louvre windows, it is aesthetically pleasing if the handles could all be at the same distance either from the ground or from the ceiling (that is aligned horizontally). Furthermore, If a handle could operate a large number of blades without damaging or destroying the operating mechanism, greater versatility would be present in placement of the handles, not only for aesthetic appeal, but also to allow mobility impaired persons (such as wheelchair persons) to operate a louvre window where are otherwise the handle may be placed in a position which is too high (or too low) for easy access by the mobility impaired person.
However it is not possible to simply remove the sealing rib on the end clip in order to reduce the load placed on the operating system, as this will now reduce the weatherproofing of the entire louvre window.
It is known to open larger louvre structures using assistance from pneumatic rams, but this requires pressure piping to be installed around the frame and greatly adds to the cost. Large helical springs have also been used to assist in movement of larger louvres (typically steel or metal louvres) for fire ventilation.
Various types of louvre actuating devices are known to open and close the louvre blades. A typical and very common louvre operating mechanism comprises a pair of flat metal rods which are positioned within the U-shaped channel. The louvre end clip is attached to the bearing. The bearing has a rear face containing two spaced apart stubby pins. One metal rod is attached to one of the pins and the other metal rod is attached to the other pin. The rods reciprocate in opposite directions and are controlled by an external handle. Movement of the handle either upwardly or downwardly causes one of the rods to move one way and the other rod to move the other way which in turn rotates the bearing and therefore the end clip and therefore the louvre between the closed and the open positions. The pair of flat metal rods connects between 4-6 end clips to rotate together upon operation of the handle.
With this system, the short stubby pins which are attached to the bars exhibit quite strong forces upon operation of the louvre operating mechanism. Importantly, these pins exhibit a bending force as well as a shear force. While the pins are typically strong enough to withstand the shear forces, it is found that most failure of the louvre operating mechanism occurs when the pins break due to the bending force. Therefore, it would be an advantage if it was possible to develop a louvre operating mechanism which would place less bending force on the pins.
Another disadvantage with this conventional system is the requirement to process and assemble two bars into the U-shaped channel as part of the manufacture of the operating system. The heads of the pins need to be permanently deformed to hold the bars in position. This requires specialised assembly equipment, and once the operating system is assembled no part of the assembly can be readily replaced. Therefore, if, say, one of the pins is damaged, it is necessary to remove the entire louvre operating system and to replace it. This is quite expensive and laborious.
It is known to provide a louvre operating mechanism which has only a single bar. This provides certain advantages over the assembly described above. Typically, the single bar is a rack and pinion system where the bar is provided with a rack (a type of tooth structure), and the bearing (to which the end clip is attached) is provided with some sort of pinion arrangement. It is essential that the teeth on the rack and the teeth on the pinion are formed in the correct shape which requires both to be moulded components. The bar containing the rack is formed into smaller sections which are joined together such that the required number of blades can be operated with a single handle. It is extremely important that the spacing between the racks on the bar is exactly correct, otherwise operation of the handle will result in louvre blades closing or opening in a nonuniform manner. For instance, one louvre blade could be in the fully closed position while an adjacent louvre blade is in the almost closed position and this is certainly undesirable. Therefore, the manufacture and the assembly of this type of louvre operating system is expensive and requires extreme accuracy.
The large majority of louvre systems manufactured in the world today rely on a simple handle and link systems to operate the louvre mechanism (open and close the louvre blades). This simple handle/link also provides complete and positive closure of the window by means of the handle/link joint being forced over-centre via an intuitive action of pushing the handle into a closed position.
The handle/link joint is constructed using a purpose made rivet or stud with the link being attached to either the top or bottom face of the handle. The method of attaching the link to one face of the handle via a rivet results in flexing of this joint when locking—over centre closing)—pressure is applied to the system (tests have confirmed that there is a correlation between locking pressure, blade to blade contact, and water penetration resistance). Because one member is placed on top of the other member and then joined together via a rivet, the acting/reacting forces are not in alignment with each other which introduces a bending moment at the joint, which in turn results in flexing of the joint. This flexing of the joint ultimately results in failure of the joint (the most common failure being that the rivet either breaks, or pulls out of the link).
It would be an advantage if it were possible to minimise or eliminate this disadvantage.
Australian patent application 23966/88 is directed to a louvre clip assembly. The assembly has a louvre clip containing internal voids. The voids are weight reducing voids and do not appear to be used for any draining reason.
Australian patent application 23297/95 describes a louvre system containing last louvres and metal louvres. The lower end of the metal louvre is curved to form a gutter. The gutter drains water from the louvre into the vertical side jamb, which is provided with a drainage hole to drain water to the bottom and to the outside of the jamb. The louvre end clips to not contain any drainage channels.
U.S. Pat. No. 4,226,051 is directed to a louvre window. The louvre glass is fitted into an end clip which contains a reinforcing element which forms an enclosed void. This void does not appear to be used for drainage.
European patent application 432828 describes an end clip and particularly a moulded end clip which has a substantially hollow interior. The interior does not appear to be used to drain water.
U.S. Pat. No. 1,830,487 shows a louvre for windows and FIG. 6 appears to show a small internal void but this void does not appear to be used to drain water.
U.S. Pat. No. 4,310,993 describes a gutter arrangements and a down spout arrangement but the arrangement does not form part of an end clip.
Japanese patent application 11325529 does not appear to show an end clip containing internal drainage channels.